Pesticide & Herbicide Application

Thread: I have shunned all pre emergence

I have never applied pre-m to my home lawn. I have only sprayed broadleaf control (a blanket) 2 times in 8 years. My lawn gets no annual grasses at all. Only 2 or 3 dandies a year. I live across from a big park loaded with weeds and crabgrass and the neighbor to the north has tons of weeds. My lawn is not real dense. It is very old and needs aerated a lot.
I think that too much herbicide causes the soil to build up some sort of immunity. Trugreen sprays Trimec 4 times a year on their lawns (here)and they just can't get long term results.

I am seriously considering not using pre-m next year and going with a post emergent.

Bluegrass rhizomes are NOT stunted to a measurable degree by Pendimethalin. Soil temperature has a much greater impact on root & shoot quality than any of the dinitroanaline herbicides (when applied at labled rates). Trifluralin (Treflan, Team, TeamPro) is the most likely to cause root alterations but don't get too hung up on this either. Again, rate & soil temp's skew most field data to the point of being almost useless. We sell boatloads of Pre-M to America's "cool-season" Bluegrass sod producers so that you can purchase weed free Bluegrass Sod. Rhizomes are their bread & butter. If any of them were significantly concerned, they'd stop using pre's and the only ones that have, just don't have weed pressure. So they save the money if they can.
Drive does allow for agressive spring seeding successes. Just make sure you add a "Pre" to Drive since it only acts as a "Pre" itself for about 4 weeks. Not long enough in the Northeast anyway.